Electroscope



July 21, 1931. R, ARTQN 1,815,606

' ELECTROSCOPE Filed Sept. 27. 1929 Patented July 21, 1931 UNITED STATES PATENToI-'FICE ROGER BARTON, OF CHICAGO, ILLINOIS, TO CENTRAL SCIENTIFIC COMPANY, A. CORPORATION OF VI1'.|LII\`I'OIS nLEo'rRosooria Application filed September 27, 1929. Serial No.395,509.`

The invention relates to electroscopes of the type in which the indicating element is a sheet of gold-leaf or other suitbale material, its object being to increase the durability and sensitiveness of the instrument.

An embodiment of the invention is hereinafter described and is illustrated in the accompanying drawings, in which Fig. 1 is an elevation of the instrument;

F ig. 2 is a detail in perspective of the lower portion of the inductive element, with the indicating element mounted thereon;

lig. 3 is a detail of the indicating element; an

Fig. 4 is a face view of the indicating element before mounting, some portions being broken away.

The instrument is mounted upon any suitable standard, as 10, and comprises a cham- 20 bered body, as shown at 11, circular in form and having removable, transparent side wallsV The inductive element is in the form of a rod 14, which projects through, and is suit- Y ably secured to, the circular wall ofthe casing. The outer end of the inductive element is, as usual, provided with a ball or knob 15 to cooperate with a body the electrication of which is to be tested. Mounted upon the outer end of the rod 14 and between the ball 15 and the casing is a cup-shaped element 16 which serves to obviate radio-active influences. l

The inner Vor lower end of the inductive in the form of a metal plateV 17, rigidly secured to the end of the element 14. The plate 17 is rectangular in form and is stiifened by having its side margins bent to angle form. The upper portion of the plate 17 is apertured, as indicated at 18, and flanking the lower end of this aperture are trunnion lugs 19, 20 which may, as shown, be formed as integral with the plate, being bent upwardly perpendicular to the face of the plate and apertured to loosely receive a pivot rod 21. Preferably, this rod is a thin bar and rests Within the lug apertures upon one of its side margins which is brought to a knife edge. The lugs 19 and 2O are provided with outelement is provided with a flattened'portion` wardly and downwardly turned portions, as at 22,1 which overlap the ends of the rod` 21 preventing its longitudinal shifting.

The indicating element is apsmall sheet of Vgold-leaf 23, reinforced by a backing of high grade Japanese lens paper or the like, the two sheets being secured together by means of animal glue. A suitable stain may be mixed with the animal glue for `the purpose of giving to the laminated leaf structure an appearance in all ways akin to the pure gold leaf. After cementing the paper .to the gold leaf, it may be further made into a homogeneous structure by pressingwith a hot sad- -1ron. Y

The composite indicating element is then secured toa flat face of the rod 21 by a suitable cement and it is further reinforced by havingits side margins folded upwardly,- as

shown at25, 26. The upper ends of these ifvmarginal portionsV are preferably Vfolded against, and cemented to, the face of the gold leaf, as indicated in the drawings. A

The indicating element is counterbalanced `by a rod 27 secured `tothe rear face of the indicating element 23 and projecting upwardly therefrom. The proper'weight for the counterbalance is readily secured by attaching to its upper end a lump 28 of awaxy materiahsuchas parajflin, whose mass maybe readily added to or subtracted from by manipulation of a hot needle.

The instrument, as thus described, has the requisite sensitiveness as the indicating ele-V ment will swing very freely, the pivot rod being practically frictionless. The reinforcement of the indicating element, as described, prevents its flexure and consequently greatly prolongs its life.

The operation of the instrument, except for the pivotal Vaction of the indicating element, is the same as in electroscopes heretofore in use, the polarization of the inductive element causing the outward swinging of the indicating element because it is charged with electricity of the same sign as is the lower end of the inductive element.

I claim as my invention:

1. An electroscope comprising a stand and a casing mounted on the stand and having a.

transparent Wall, an inductive element Within the casing and projecting through the top thereof, the lower end portion of the element being flat, a pivot rod journaled across the flat portion and spaced from the end thereof, and a sheet of gold leaf depending from the rod.

2. An electroscope comprising an inductive element, a pivot rod supported by the element adjacent one of the ends thereof, a sheet of golf leaf attached to the rod, and means for stiifening the sheet.

3. An electros'cope comprising an inductive element, a pivot rod supported by the element adjacent one of the Vends thereof, and a sheet of gold leaf reinforced by a sheet of paper cemented to its surface.

4. An electroscope comprising an inductive element, a pivot rod supported by the element adjacent one of the ends thereof, and a sheet of gold leaf attached to the rod, the side margins of the sheet being turned up- Wardly.

5. An indicating element for electroscopes I comprising a sheet of gold leaf and a sheet of lens paper cemented together.

6. In an electroscope a. fixed inductive element, and an oscillating reinforced gold leaf element pivotally attached thereto, and a counterpoise for the last-named element.

7. The method of making a composite gold leaf for electroscopeswhich comprises taking a sheet of gold leaf, securing to the leaf a sheet of thin reinforcing paper by amixture y consistingrof animal glue and a stain, and

thereafter pressing the composite structure intoV intimate contact by the application of pressure and heat.

8. As an article of manufacture, a composite gold leaf for use in electroscopes comprisinga sheet of gold leaf reinforced by and in intimate Contact With a sheet of relatively light paper, saidgold leaf and reinforcing paper being pressed together to form a subr stantially homogeneous sheet of material.

In'testimony whereof I afxmy signature.

ROGER BARTON. 

